COMPASS Pathways : Presentation – February 2022

Transforming mental health care

COMPASS Pathways plc

February 2022

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Market & Industry Data Projections, estimates, industry data and information contained in this presentation, including the Company's general expectations and market position and

market opportunity, are based on information from third-party sources and management estimates. Although the Company believes that its third party-sources are reliable, the Company cannot guarantee the accuracy or completeness of its sources. The Company's estimates are derived from third-party sources, publicly available information, the Company's knowledge of its industry and assumptions based on such information and knowledge. The Company's estimates have not been verified by any independent source. All of the projections, estimates, market data and industry information used in this presentation involve a number of assumptions and limitations, and you are cautioned not to give undue weight to such information. In addition, projections, estimates and assumptions relating to the Company's and its industry's future performance are necessarily subject to a high degree of uncertainty and risk due to a variety of factors, including, but not limited to, those described above, that could cause future performance to differ materially from the Company's expressed projections, estimates and assumptions or those provided by third parties. This presentation shall not constitute an offer to sell or the solicitation of an offer to buy securities, nor shall there be any sale of securities in any state or jurisdiction in which such offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of any such state or jurisdiction.

For additional disclosure regarding these and other risks faced by the Company, see the disclosure contained in the Company's public filings with the US Securities and Exchange Commission (the "SEC"). Except as required by applicable law, we do not plan to publicly update or revise any forward-looking statements contained herein, whether as a result of any new information, future events, changed circumstances or otherwise. Although we believe the expectations reflected in such forward-looking statements are reasonable, we can give no assurance that such expectations will prove to be correct. Accordingly, readers are cautioned not to place undue reliance on these forward-looking statements. No representations or warranties (expressed or implied) are made about the accuracy of any such forward-looking statements.

© COMPASS Pathways 2021

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Pioneering the development of a new model of psilocybin therapy

2021 Key achievements

• Progressed COMP360 development program with positive phase IIb clinical trial results - 25mg dose selected for phase III program; program has Breakthrough Therapy designation

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SSRI combination study supports potential adjunctive use of COMP360

Full pipeline of COMP360 trials underway in multiple IISs exploring range of indications

New patents awarded bringing total granted to 10 - numerous additional patents under review Experienced leadership team, board of directors, scientific advisory network

COMP360 phase II study launched in PTSD

Aquilino Cancer Center completes positive COMP360 psilocybin therapy study with simultaneous administration and 1:1 therapist support

• Data published in The New England Journal of Medicine on COMP360 in MDD from Imperial College London

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Advanced preclinical studies in new indications; Discovery Center expanded Established first Centre of Excellence

COMPASS well capitalized from successful IPO and follow-on financings

Note: TRD = treatment-resistant depression; PTSD = post traumatic stress disorder

© COMPASS Pathways 2021

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Everyone has a

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We are a mental health care company

Dedicated to accelerating patient access to evidence-based innovation in mental health care

• Significant unmet need: 100m people1 with treatment-resistant depression (TRD)
• Committed to transforming the patient experience

Developing COMP360 psilocybin therapy for TRD

• COMP360 purified psilocybin formulation designated a FDA Breakthrough Therapy for TRD

• Completed phase I healthy volunteers trial
• Completed phase IIb - world's largest psilocybin therapy clinical trial
• Completed SSRI as adjunct to COMP360 open-label study
• Planned expansion into additional indications

Driven by science and rigour

• COMP360 differentiated mechanism of action, activating the 5HT2A receptor2

• Signals from academic studies have shown that psilocybin therapy can improve outcomes for patients
• IP strategy combining patent protection with regulatory and market exclusivity

Source: 1. Depression and Other Common Mental Disorders: Global Health Estimates and Cleare, A. et al - 2015 -Evidence-based
guidelines for treating depressive disorders with antidepressants: A revision of the 2008 British Association for Psychopharmacology
guidelines. These sources state that 1/3 of those suffering with major depressive disorder (MDD) are estimated to be TRD. Therefore, we
approximated 100 million from 320 million people with MDD 2. Halberstadt and Geyer - 2011	4